Electric ray producing device



May 12, 1936, T, MclLVAlNE 2,040,753

ELECTRIC RAY PRODUCING DEVICE Filed Feb. 5, 1930 5 Mia 17% Patented May12, 1936 ELECTRIC RAY PRODUCING DEVICE cm '1'. Mcllvaine, Cleveland,Ohio, assimor to Mcllvaine Patent Corporation, St. Charles, 111., acorporation of Delaware Application February a, 1930, Serial No. 425,455

13 Claims. .(Cl. 176- 1) This invention relates to electricray-producing devices and has for its objects the provision of animproved lamp of the bulb type adapted to produce a mixture of all kindsof rays, viz: infrared, visible, actinic, and ultra-violet capable ofaifording the physiological effects of sunlight and with a minimum ofcomplication, expense, or servicing requirements and also with a minimumof apparatus such as transformers, coils and the like. Another object ofthe invention is the provision of means for reducing the tendency ofmetallic arcs or gas-discharge apparatus to blacken the container wallsby sputtering. Another object of the invention is the provision of asimple and inexpensive lamp which shall produce a very large amount oflight. Another object of the invention is the production of a whitelight containing all wave lengths, and at a high efiiciency ratio oflight production to energy consumed. Further objects and advantages ofthe invention will be apparent as the description proceeds.

In the drawing accompanying and forming a part of this application Ihave shown a few specimen embodiments of my inventive idea. Fig. 1 is avertical sectional view through a complete lamp containing myimprovements but designed for rather low voltage; Fig. 2 is a sectionalview drawn to a rather large scale showing the relation of thelight-giving parts; Figs. 3 to 'l inclusive show modified arrangementsof the light-giving parts, the two last mentioned being arranged for 110volt operation without transformers; and Fig. 8 illustrates a modifiedform of lamp base provided with a resistance and heat-producing elementin lieu of a transformer.

My improved lamp combines the principle of filament operation and thatof positive-column discharge illumination. It preferably comprises aglass container or globe I having a neck 2 fitted with a flange 3provided with a tube 4 and press 5. Sealed in the press are leading-inwires 6 and I between whichis connected the filament 8. 1. ii j--;'3

Carried by the two leading-in wires and facing.

' each other are electrodes ill- 40 for the positive column discharge.These in their preferred form are made of hollow helical coils oftungsten wire the turns laid closely together, the interiors opensimplest type of lamp when the globe is provided with a filling ofeasily-ionizable gas such as argon, neon, helium, etc., at a pressurefrom 1 to 300 mm. of mercury and preferably between about to 100 mm.when a current is applied to such a lamp the glowing filament soonionizes the gas to the point where an independent discharge begins totake place between the electrodes l 0--lli resulting in a great increasein the amount of light produced, this light also proving very rich inultra-violet and actinic rays. It should be noted, although I have notillustrated the same, that provision should ordinarily be made forcontrolling the amount of current either manually or automatically sincethe discharge path by way of the electrodes as soon as establishedordinarily exhibits much less resistance than the filament, so that anexcessive current can easily be developed unless suitable precautionsare taken. These precautions can consist of manually connecting the lampthrough a higher resistance or to a source of lower potential as will beobvious, or by employing what is known as a constant cur.- renttransformer.

Such an intense positive-column discharge always tends to produce whatis known as sputtering of the electrodes with consequent blackening ofthe container-walls. I have found that the employment of coiled tungstenwire is of peculiar advantage in preventing this since the me- 30chanically-treated and drawn wire has a greater density than other formsof the metal, and because such hollow electrode carries most of itsdischarge on the interior, thereby confining the sputtering to theinside of the electrode, and 35 preventing or at least retarding theblackening of the globe or container. The advantages of the hollowelectrode can of course be enjoyed without making'the electrode ofcoiled wire. In Fig. 4 I have shown the electrodes as consisting 0 ofpressed cups |2--l2 of tungsten carried by the wires 6 and l' and facingeach other.

The very great intensity of the discharge however causes it to tend tooverrun onto the exterior of these electrodes and to oppose and diminish5 this tendency I preferably surround each electrode with a spacedinsulated wire coil [3 parallel and more or less accurately concentrictherewith, although the latter point is of comparatively smallimportance within wide limits. Preferably these coils |3l3 are spacedentirely apart and insulated, a separate coil 'for each electrode. InFig. '1 I have shown these coils as sealed to a glass header 14 carriedby the leading-in wires. In Fig. 5 I have shown them as carried by aglass header i5 sealed in the press. The operation of these coilsdepends upon the fact that insulated metallic bodies of this nature,located inside such a container, tend to pick up stray electrons until aconsiderable charge is accumulated, and this charge exhibits thephenomenon of repelling the cathode glow and causing it to confineitself inside the electrodes, at least throughout a much larger range ofcurrent-densities than otherwise. This arrangement effectually preventsor retards the blacking of the bulb interior.

It is also within my invention, and frequently a desirable step, toinclude in the bulb or container a small quantity of mercury I6 whichhas the properties of increasing the conductivity of the medium andhence the proportion of ultra-violet radiation and ofincreasing theintensity of the arc. This also renders the device much more efiicientas a producer of light, the light emitted greatly increasing and theelectromotive force decreasing even with constant current, say voltsdown to 10 volts across gap.

of course it is also possible and within my invention to coat theinterior of the electrodes with emission-facilitating material, such forexample as alkali metals, thorium, caesium and other known emissivesubstances.

The form of the device shown in Figs. 1 to 5 inclusive is designed torun at less than 110 volts, for example about to volts starting, and 15to 20 volts running, at which potential it utilizes about 400 watts andafiords a dazzling, intensity of light. In Figs. 6 and 7 I have shownmodifications to facilitate the use of the lamp on 110 volt circuitwithout special transformer. The press 5 carries a post 20 of insulatingmaterial from which project the spaced wires 2! carrying spacedelectrodes 22 each of which is preferably a hollow cylinder'ofhighly-resistant metal such as tung-' stem or other metal having amelting point above 2300 C. The terminal wires 2| are extended beyondthe rest and connected by'the filament 23 and also connected one to eachof the leading-in wires, one of the latter being preferably surroundedby a glass-tube 24 to avoid accidental arcing.

In the form of the invention'shown in Fig. 6 the two terminal electrodes22 are carried directly by the terminal wires 2 l in the modificationshown in Fig. 7 the terminal electrodes 22 are connected to the terminalwires by filaments 25 of such size as to tend to hold the current in theare constant after starting. For example the filament 23 shown in Fig. 7may be a 110 watt filament, while the arcs between the diiferentelectrodes will carry a 500 watt current when once started, theresistance of the filaments 25 being so chosen as to limit thecurrent-consumption to this point. In Fig. 7 I have also shown eachelectrode as surrounded by an insulated wire coil l3 for the purposeabove described.

When the electrodes in series are above two in number it becomesimportant to provide means for leaking-oil any collected potential fromtheintermediate electrodes. providing any conductive path, for exampleby blackening the surface of the post 20 in a gas flame, or bysuificiently reducing the lead content of the glass by a reducing flame,or by applying a thin metallic film. Another mode is by connecting eachof the intermediate electrodes to corresponding points of the filament,either by the conductor leads 21 shown in Fig. 6 or by fine filamentleads 28 as shown in Fig. '7. When grid coils l3 are also employed asshown in Fig. 7

This can be done by the post must, of course, be kept free from anyconductive layer, and the filaments 28 must be kept out of contact withthe grid-coils, though no care in spacing is necessary since no arcingcan occur.

In Fig. 8 I have shown another mode of holding detail can be madewithout departure from the scope of my inventive idea.

Having. thus described my invention what I claim is:

1. An electric lamp comprising a closed. transparent container havingtherein an atmosphere of readily ionizable gases at a pressure betweenabout 1 and 300 mm. of mercury when cold, spaced metallic electrodesinside said container, leading in wires connected to said electrodesrespectively,

and an insulated wire-coil surrounding and spaced from each of saidelectrodes, the electrodes being hollow and cylindrical and having theirad Jaoent ends open and their axes substantially parallel to the axes ofsaid coils.

2. An electric lamp comprising a closed trans parent container havingtherein an atmosphere of readily ionizable gases at a pressure betweenabout 1 and 300 mm. of mercury when cold, spaced metallic electrodesinside said container,

leading-inwires connected to said electrodes rc-- v.

spectively, and an insulated wire-coil surround ing and spaced from eachof said electrodes, electrodes being hollow and cylindrical and hav ingtheir adjacent ends open and their axes sub stantially parallel to theaxes of said coils, ir combination with a filament adjacent to saidelectrodes and adapted upon being energized to ionize the gas about saidelectrodes.

3. An electric lamp comprising a closed trans parent container havingtherein an atmosphere of readily ionizable gases at a pressure betweenabout 1 and 300 mm. of mercury when cold, spaced metallic electrodesinside said container, leading-in wires connected to said electrodesrespectively, an insulated wire-coil surrounding and electrodes, theelecspaced from each of said trodes having their axes substantiallyparallel to the axes of said coils, in combination with a filamentadjacent to said electrodes and adapted upon being energized to ionizethe gas about said electrodes, and a small quantity of mercury in sidesaid globe; out of contact with either said. filament or saidelectrodes.

4. An electric lamp comprising a closed transparent container ofglobular form, having therein an atmosphere of readily ionizable gasesat a pressure between 1 and 300 mm. when cold of mercury, said containerhaving a hollow neck projecting from its top, a pair of spaced,leadingin wires depending in said neck and having their lower endsoffset away from each other and having their adjacent portions insulatedfrom each other, an incandescible filament connecting the extremities ofsaid ofiset portions, a pair of electrodes carried by said ofisetportions above at one side of said electrodes for said filament, each ofsaid electrodes facing the other electrode and said filament having itsmiddle portion deflected downwardly away from the arc-space between saidelectrodes, an insulated wire coil surrounding and spaced from each ofsaid electrodes, and a small quantity of mercury inside said globe, outof contact with either said filaments or said electrodes.

5. Apparatus for producing electric light comprising a closed containerwhich is transparent to the rays desired, a pair of spaced hollowmetallic bodies located inside said container having open ends turnedtoward each other, metallic leading-in wires connected to said bodies, areadily ionizable gas at subatmospheric pressure in said container, andelectrostatic shields surrounding said bodies and spaced therefrom andpositioned within the container to receive and maintain a negativecharge whereby the cathode glow is confined inside said electrodes.

ionizable gases at a spaced metallic electrodes inside said container,leading-in wires connected by metallic conducting elements to saidelectrodes respectively, a filament inside said container connected as ashunt across said electrodes, and separate insulated wire coilssurrounding and spaced from each of the metallic conducting elementsinside said container whereby the arc is confined to the electrodes.

'7. In an electric lamp, a closed container having therein an atmosphereof readily ionizable noble gases at a pressure between about 10 and 300mm. of mercury when cold, spaced metallic electrodes inside saidcontainer, leading-in wires connected to said electrodes respectively, awire coil surrounding and spaced from each of said electrodes, andhaving the end portions thereof spaced apart other against an electriccircuit therethrough, and means for initiating ionization of the gases,said container being of a substance which is transparent to the wavelengths produced therein.

8. An electric lamp comprising a closed container having therein anatmosphere of readily ionizable noble gases having a subatmosphericpressure, spaced metallic electrodes inside said container, leading-inwires connected to said electrodes respectively, an incandesciblefilament permanently connected to said leading-in wires initiating theionization of the gases in said container, a hollow metallic shieldsurrounding each of said electrodes and insulated therefrom, each ofsaid shields having an opening facing the other electrode and havinginterposed towards said filament a side wall which is substantiallyimpervious to electronic penetration, and mercury in said containeradapted-to become volatllized and take part in the are as thetemperature of the same becomes increased.

9. An electric lamp comprising a closed transparent container havingtherein an atmosphere of readily ionizable gases at a pressure betweenabout 10 and 300 mm. of mercury at room temperature, spaced metallicelectrodes inside said container, leading-in wires connected to saidelecand a wire-coil surrounding and spaced from each or said electrodesand from each other, said wire-coil having the ends the electrodes beingand completely insulated from each thereof completely insulated fromeach other, the electrodes being hollow and cylindrical and having theiradjacent ends open and their axes substantially parallel to the axes ofsaid coils.

10. An electric lamp comprising a closed transparent container havingtherein an atmosphere of readily ionizable gases at a pressure betweenabout 10 and 300 mm. of mercury at room temperature, spaced metallicelectrodes inside said container, leading-in wires connected to saidelectrodes respectively, and an insulated wire-coil surrounding andspaced from each of said electrodes to prevent blackening of thecontainer, hollow and cylindrical and having their adjacent ends openand their axes substantially parallel to the axes of said coils, incombination with a filament having its ends permanently connected one toeach leading-in wire and located outside of said wire coils.

11. An electric lamp comprising a closed transparent container havingtherein an atmosphere of readily ionizable gases at a pressure betweenabout 10 and 300 mm. of mercury at room temperature, spaced metallicelectrodes inside said container having their adjoining ends opposite toand spaced from each other so as to define a gap therebetween,leading-in wires connected to said electrodes respectively, each of saidelectrodes consisting of lic wire having a melting-point above 2300?metallic electrostatic shields within the container surrounding andinsulated from said electrodes to receive a negative charge, saidelectrodes being spaced apart and having turned toward each other, andsupplementary means for ionizing the gases about said electrodes toinitiate the are.

12. An electric lamp comprising a glass globe containing one or more ofthe ionizable chemi- I atmospheric gases at a pressure cally-inactivebetween 1 and 300 mm. of mercury when cold, a pair of leading-in wiressealed in the wall of said globe and projecting into the interiorthereof, said wires being spaced from the glass walls, connecting thelower extremities of said wires and comprising a fine refractory wirewound in a helical coil, and a pair of spaced, metallic electrodescarriedone by each of said leading-in wires above and adjacent to saidfilament and a defining therebetween a positive-column-path located inmultiple-circuit with said filament, each of said electrodes comprisinga hollow, cylindrical body having solid side walls made ofelectrically-conducting substance, the hollow portions thereof beingturned toward each other.

13. An electric lamp comprising a closed transparent container havingtherein an atmosphere of readily ionizable gases at apressure between 1to 300 mm. of mercury when cold, an incandescible filament in saidcontainer, leading-in wires connected to said filament, and spacedelectrodes in said container defining a positivecolumn discharge path,one of said electrodes being connected to one of said leading-in wiresand the other of said electrodes being connectintermediate its ends forlimiting the amount of current passing through said positive-columnpath.

ORAN T. MCILVAINE.

their hollow interiors from each other and an incandescible filament ahollow helical coil of metal- C.,

